A display device such as a liquid crystal display (LCD) is a commonly used flat panel display device. As shown in FIG. 1, a manufacturing method thereof generally includes: providing two parallel substrates (lower substrate 1 and upper substrate 2), coating a sealant 6 between the two parallel substrates, and injecting liquid crystal 5 in a space defined by the two parallel substrates 1 and 2 and the sealant 6. The lower substrate is provided with a thin film field effect transistor (TFT) and the upper substrate is provided with a color filter (CF). Rotation direction of a liquid crystal molecule in a liquid crystal cell is controlled by a signal change and a voltage change applied to the TFT so as to control exiting of polarized light of each pixel point, hence realizing the displaying. At present, methods for curing the sealant in the industry are mainly classified into two types: thermocuring and ultraviolet light (UV) curing.
There are two ways for injecting the liquid crystal into the space defined by the sealant and the two substrates: the first one is an injection method in which the lower and upper substrates are firstly bonded by a sealant, one or more liquid crystal injection openings are provided in the sealant, then the liquid crystal is injected into the space between the two substrates via the liquid crystal injection openings by means of the gas pressure difference between atmosphere and vacuum under vacuum environment; the other is a one drop fill method in which the sealant is firstly coated on one substrate, the liquid crystal is distributed in the space defined by the sealant and the aforementioned substrate by a liquid crystal drop filling device, then another substrate is cell-assembled with the aforementioned substrate under vacuum environment and these two substrates are bonded firmly by curing the sealant. Since the latter way has a fast manufacturing speed and the liquid crystal material can be greatly saved, it has been mainly used in the industry recently for filling the liquid crystal.
While using the latter liquid crystal filling method, the sealant may contact the liquid crystal before curing the sealant, therefore UV curing is generally utilized to prevent contamination of the liquid crystal caused by directly contacting between the liquid crystal and the sealant. The so-called UV curing is generally to shield a liquid crystal region (also known as an effective display region, namely A/A region) by a shield (a mask) so as to expose regions coated with the sealant to perform the UV curing to the sealant with a UV curing equipment, and the mask is generally called a UV mask. FIG. 2 shows a structural schematic view of a current UV mask in prior art, a UV mask 8 is fabricated from opaque metal (generally gate metal or data metal) on a base substrate 7 by deposition, masking, etching, photoresist stripping (PR strip).
In general, while fabricating a LCD, in addition to a mask for a TFT (array) substrate and a mask for a CF (color filter) substrate, an additional special mask is required to fabricate the UV mask, so the fabrication cost of the display device will be increased.